Unit Testing in iOS

Hey Folks,

I enjoyed working with Unit Testing. So decided to make a demonstration for you all.
Hope you find it helpful.

What is Unit testing

• The smallest part of any software development task in which the units are tested for proper and smooth workout. 
• It can be done manually and automated too.

Why should I write Test Cases or do Unit testing

• Helps to define a problem and find all its positive & negative solutions.
• Gives better understanding of each small task or code.

Things that should definitely be covered or tested in a Unit Test

• Boundary Values
• Expected Values
• Stress Testing for Loops
• Out of Bound values
• Nil / NULL check

Working with OCUnit in XCode

• OCUnit is built in XCode
• When you check Use Unit Testing on New Project template wizard the setup is already done for you.

Lets start by Adding Unit Test Target to an existing project

• Right Click on Target
• iOS
• Test
• Choose iOS Unit Testing Bundle

Working on New Project with Test Targets

• Start xCode
• Choose a Single View Application
• Choose options for your new project
• Remember to check on "Include Unit Tests"

• This is the Project Navigator

• This is the sample code structure available for Test file 

XCTestCase Class

• It is a subclass of XCTest and is the Override points for writing test cases
• This class can have multiple methods & supports the Setup & TearDown methods
• Setup & TearDown methods execute BEFORE & AFTER every test method
• Test methods are instance methods
• Test methods accept NO PARAMETERS & have NO RETURN VALUE
• Test methods are prefixed with "test" keyword
• Being prefixed they are automatically recognized as test methods by the framework

How to add XCTestCase Class Files

• Right Click on Tests
• New File
• iOS
• Source
• Unit Test Case Class 
• Provide a Name, must be suffixed with keyword Tests

Some Testing Code

• To compare Objects

                         XCTAssertEqualObjects(String to compare, my string, @"comments");

• To check date accuracy or precision of values

                        XCTAssertEqualWithAccuracy(Date to compare, date that I set , 0.001);

• To check if dictionary has nil value

                        XCTAssertNotNil(dict);

• To Check true / false value

                        XCTAssertTrue(BOOL value returned from any method,

                                                  @”Can be used for conformsToProtocols”);

                        XCTAssertFalse(BOOL value returned form  method,

                                                  @"Generates a failure when ((a expression) != false)");

• To test performance or execution Time

                        [self measureBlock:^ { [self anyMethod]; } ] ;

How to Execute Tests

• Command + U
• OR Product > Test

View status of all Tests executed

• The Green Tick indicates the Success.
• If it is Red then it indicates an Error.
• Same images appear in reader view before each method

Enable XCode Code Coverage Reports

• Product > Scheme > Edit Scheme
• Choose Test Scheme > Tick "Gather Coverage Data"

View Reports in XCode

• Command + 8
• OR View > Navigators > Report Navigators

Some Info...

• What happens if i remove Setup and tear down?? 
• No issue arises

• Can I run single test?? 
• YES, you can :  Control-Option-Command-U

• Running xCode Tests from Terminal
• xcodebuild test -scheme OpenPage2 -project OpenPage2.xcodeproj -configuration Debug -sdk iphonesimulator
• It clearly states that  Unit Tests are not supported by the Simulator. To avoid this add TEST_HOST='' to the end of the xcodebuild command. 
• Run the tests from the terminal again. 

Hope you find it helpful :)